Backing device for propeller-driven vessels



MAY 14, 1940. N, J. DlDRlKsEN 2,200,836

BACKING DEVICE FOR PROPELLER-DRIVEN VESSELS Filed April 5, 1938 Fig. l.

Patented May 14, 1940 UNITED STATES BACKING DEVICE FOR. PROPELLER-DRIVEN VESSELS Niels Jergen Didriksen, Odense, Denmark Application April 5, 1938, Serial No. 200,186 In Denmark April 5, 193'?v 3 Claims.

The invention relates to an apparatus enabling propeller-driven vessels. to back and to be steered during backing and to swing, if they are not moving forward. v

The invention has for its object to attain the advantage that these various motions of the vessel can be performed,'without any alterations in the propeller being made, i. e. without the direction of revolution of the propeller nor the direction of the pitch of the propeller blades being altered.

This object is attained by means of an apparatus described in detail with reference to the accompanying drawing which shows a construction of the invention. The latter, however, is not restricted to the construction thus shown.

Fig. l shows the apparatus disposed on a Vessel, in side elevation,

Fig. 2 the apparatus in plan view, and

Fig. 3 the apparatus in front elevation.

On the drawing, B is the aft part of the vessel, C is a space opening downward in which the apparatus can be raised and lowered, D is the stern, E is the keel, F is the stern tube, G is the propeller shaft, H is the propeller, I is the tube, J is the heel and L is a bulkhead.

The container A, the aft side of which, as shown in Fig. 2, is rounded in order to offer the least possible resistance in the water during backing is divided into two compartments by a vertical bulkhead a extending through the entire height of the container. The front space can receive the propeller water by way of an opening of the same size as the area described by the propeller blades during their rotation. The opening is lined by a flange b, about :V8 inch wide bent inward, the said flange having for its object to prevent the entering propeller water from flowing back. By means of a vertical distributing member K, which as shown in Fig. 2 is V-shaped in horizontal section, with its point facing the propeller, and which lits as tightly as possible to the bottom and top side of the vessel A, the propeller water can be divided and then be pressed out through the two side openings of the container A, which in a horizontal plane through the vessel form acute angles of about with `the diametral plane. In order to counteract suction from the propeller of the water discharged from the side openings, the latter are narrowed directly at the outlets, wedgeshaped strips p and p1 being screwed ,on to the Ainner faces next to the propeller, for the purpose of throwing the escaping water away from the propeller. The distributing member K is tted,

at the four lower corners, with metal rollers, in order to facilitate the motions thereof. In the aft compartment of the container A. at the level of the centre of the bulkhead a., a horizontal screw-spindle d' is supported in two bearings, the 5 said spindle being adapted to move a screwhead c, which by way of a horizontal incision in the bulkhead a, is attached to the distributing member K. The said incision, the length of which is determined by the distance through `10 which the distributing member is to be moved, is covered in the front compartment of the container A by a metal band f, the end points of which are screwed to the bulkhead a somewhat beyond the end points of the incision, and which passes through a special opening cut in the distributing member. The pressure of the propeller water will press the metal band against the bulkhead a, and will thereby close this aperture, and during its horizontal motions the distributing member K will lift the metal band in such a manner that the said band will not impede the motions. By the provision of this band f, the advantage is attained that no propeller water is wasted ineffectively in the aft compartment of the container A. By way of bevel gears e, the screw spindle d can be rotated by a Vertical shaft 1, the upper end of which is connected to a sloping operating rod 1c, k1 by means of a Cardan link i. The upper half 7c of the operating rod consists of a pipe through which the lower half k1 o the rod can slide while the container A is being raised and lowered, a key being provided on the inside of the tube lc and a corresponding groove throughout the entire length of the rod 35 k1. The bearing for the rod 7c is attached by means of a Cardan link l to the upper edge of the bulkhead L, and is tted at its upper end with a hand Wheel m, by the rotation of which the distributing member can be adjusted.

The container A is mounted on the vessel in such a manner that it is connected thereto by six points of support or bearings. The main points of support are two roller bearings o, at the upper and lower edge of the container A, respectively, a supporting rod g passing through the aft compartment of the container and having its lower end screwed into the heel J of the vessel, while the upper end thereof is screwed to the stern D of the ves-sel, at such a level that the container A can be moved into its raised position. Two bearings 7', i in which the bracing rods' h and h1 can slide are provided, at the bottom edge of the bulkhead and somewhat higher up, on each of two rails screwed to the bulkhead L opposite thersaid two bracing rods h and h1. The bracing rods h and h1 are disposed in the two cavities formed in the container A in the spaces between the entrance opening for the propeller water and the two side openings, and they are attached to the bottom of the, container A by means of reinforcements. 'Ihe bracing rods h and h1, the length of which above the vessel is determined by the required length of motion ofthe vessel A, are interconnected at the top, and a bracing against the top edge of the container A is provided as shown in Fig. 3.

During the forward motion of the vessel, the container A is maintained in itsy raised position by means of a wire rope n attached to the container by means of a clip. f

The steering of the vessel, while sailing forward, is eected in the ordinary manner by means of the rudder, which is disposed directly behind the stern and the bracing rod a. If backing of the vessel is desired, the wire rope n is slackened, after which the container A sinks by gravity into the backingA position, which is adjusted in such a manner that the entrance opening for the propeller water in thel vessel A stands at the same level as the propeller, when the container is resting on the heel J of the vessel. The backing is effected in that the propeller water is directed into the front compartmentv of the container A, where the distributing sel, a deflector container for the screw water having a forward facing inlet openingand two lateral discharge openings facing obliquely forward in substantially opposite directions, avertical dividing plate disposed in said deflector container rearwardly of said inlet opening, andl means to adjust said deilector container to a position rearwardly of the propeller with said inlet opening facing the latter.

2. A device, as claimed in claim 1, comprising further means forsidewise displacing said vertical dividing plate.

3. A device, as claimed in claim 1, comprising further a chamber rearwardly of said deector container and a mechanism disposed in said chamber for sidewise displacing said vertical dividing plate.

NTELs JQRGENDIDRIKSEN. Y3o 

